This invention relates to clamps for use with completion or production tubing strings deployed in oil, gas or water wells.
The completion of a well using tubing conveyed tools and the subsequent production thereof with or without the use of a submersible pump suspended on a production tubing string require the installation of an electric power cable and/or service lines, for example control or injection lines, alongside the tubing string. Clearly, these cable and/or service lines are liable to be damaged during running-in and removal from the well, particularly by crushing from side loads imposed by movement in deviated wells.
It is common practice to use clamps to maintain the cable and/or lines in a pre-determined path in the space between the tubing string and the well casing, the clamps either being secured to the tubing string between couplings or spanning a coupling. Such clamps, as described for example in UK Patent Application No 2 149 000 A (Lasalle) reduce the tensile stresses to which the cable and service lines are subject by virtue of their own weight. However, conventional clamps function by compressing the cable and service lines against the tubing string. This arrangement has the drawback that the contact surfaces between the cable and lines and the tubing string are quite limited, and the support afforded is dependent on the actual diameter of the tubing string.